JWT Decoder
Decode and inspect JSON Web Tokens instantly. View header, payload, and signature. Check expiration and claims — 100% client-side, your tokens never leave your browser.
About This Tool
- 100% client-side — your tokens never leave your browser
- Instantly decode JWT header and payload
- Automatic expiration checking with time remaining
- Completely free with no registration required
Frequently Asked Questions
A JSON Web Token (JWT) is a compact, URL-safe way to represent claims between two parties. It's commonly used for authentication and authorization in web applications and APIs.
A JWT has three parts separated by dots: the Header (algorithm and type), the Payload (claims/data), and the Signature (verification). Each part is Base64URL-encoded.
Yes! All decoding happens entirely in your browser. Your token is never sent to any server. However, never share JWTs containing sensitive data publicly.
This tool decodes and inspects JWTs but does not verify signatures, as that requires the signing secret or public key. It's designed for debugging and inspection.
Yes, completely free with no registration. Decode as many JWTs as you need.